Corrosion resistance of three austenitic stainless steels for biomedical applications

Abstract

The resistance to localized corrosion of three austenitic stainless steels (SS), specifically the ASTM F-138 which is widely used in several biomedical applications, the DIN 1.4460 high N, and the DIN 1.4970 was investigated in this study by electrochemical techniques including potentiodynamic polarization and electrochemical impedance spectroscopy measurements in a phosphatebuffered solution. The DIN 1.4460 high N and the DIN 1.4970 were tested in this study for the reason they do not form any ferromagnetic phases, such as delta-ferrite or martensite, although these phases might be formed in the first type of SS. Although all the three SS tested are prone to localized attack, the DIN 1.4460 high N presented the highest corrosion resistance among the SS followed by the DIN 1.4970 and finally the ASTM F-138. Shallower and smaller pits were formed on the DIN 1.4970 compared to the ASTM F-138 SS.